Work is in progress concerning the mechanism of stimulus-secretion coupling by pancreatic acinar and other cells and the mechanism of catecholamine action on brown adipocites. These studies are directed at interrelationships between membrane electrical phenomena, Ca ions cyclic AMP and microtubules and utilize electrophysiological, ultrastructural and biochemical techniques. We are currently studying the ionic requirement for secretion by isolated pancreatic acinar cells and the effect of secretagogues on pancreatic acinar cells and the effect of secretagogues on transmembrane ion fluxes. The effects of antimicrotubular agents are being studied on enzyme release and ultrastructure of pancreatic lobules. The effects of adrenergic agonists and antagonists on the membrane potential of brown adipose tissue cells is being studied to try to determine the relationship between depolarization and lypolysis.